During warm up of an internal combustion engine, the engine block structure acts as a large heat sink because the thermal inertia of the engine block structure is an order of magnitude greater than the coolant and oil. As a result, the engine block structure takes longer to warm up than the oil.
By way of example, hot oil returning from a piston cooling gallery, which has been heated by the combustion events, may hit a crank of the engine and the oil may be thrown against the cooler crankcase. When the oil is thrown against the crankcase wall, the oil loses heat due to the large thermal inertia of the crankcase and the large surface area of the crankcase. Similarly, oil returning from the cylinder head has been heated and loses heat as it returns through the engine block to the oil sump. The resulting colder oil has a higher viscosity, which leads to higher friction losses. This in turn leads to worse fuel consumption and cabin heating.
As such in one approach, a crankcase assembly for an engine is provided. The crankcase assembly includes a crankcase comprising a crank sump, the crank sump including a primary sump volume and a secondary sump volume, one or more crankcase oil catchers, the crankcase oil catchers comprising one or more surfaces configured to catch dispersed oil in the crankcase and direct the oil along the surfaces of the crankcase oil catcher away from a crankcase casing wall and towards the crank sump, wherein the crankcase oil catchers are provided above a crankshaft and below an associated piston of the engine, and one or more guides configured to collect oil captured by the crankcase oil catchers and guide the oil to the primary sump volume.
The above advantages and other advantages, and features of the present description will be readily apparent from the following Detailed Description when taken alone or in connection with the accompanying drawings.
It should be understood that the summary above is provided to introduce in simplified form a selection of concepts that are further described in the detailed description. It is not meant to identify key or essential features of the claimed subject matter, the scope of which is defined uniquely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that solve any disadvantages noted above or in any part of this disclosure.